Problem: $J$ $K$ $L$ If: $ KL = 9x + 3$, $ JL = 55$, and $ JK = 7x + 4$, Find $KL$.
From the diagram, we can see that the total length of ${JL}$ is the sum of ${JK}$ and ${KL}$ $ {JK} + {KL} = {JL}$ Substitute in the expressions that were given for each length: $ {7x + 4} + {9x + 3} = {55}$ Combine like terms: $ 16x + 7 = {55}$ Subtract $7$ from both sides: $ 16x = 48$ Divide both sides by $16$ to find $x$ $ x = 3$ Substitute $3$ for $x$ in the expression that was given for $KL$ $ KL = 9({3}) + 3$ Simplify: $ {KL = 27 + 3}$ Simplify to find ${KL}$ : $ {KL = 30}$